1. Field of the Invention
The invention relates to a vehicle control system that is configured to control behavior characteristics or acceleration/deceleration characteristics (which will be called “running characteristics”) of the vehicle, such as a power characteristic, steering characteristic and a suspension characteristic of the vehicle, so that the running characteristics match a running environment and driver's preferences and intention regarding running.
2. Description of the Related Art
While the vehicle behavior, such as a vehicle speed and a running direction, varies according to the driver's accelerating/decelerating operation and steering operation, the relationship between the amount of the driver's operation and the amount of change of the behavior is determined not only by the energy efficiency, such as a fuel efficiency, but also by characteristics, such as a ride comfort, quietness and power performance, which are required of the vehicle. In the meantime, environments in which the vehicle runs include a wide variety of surroundings or road types, such as an urban area, an expressway, a winding road, an uphill, and a downhill, and there are a variety of driver's preferences and intentions regarding running, and there are a variety of impressions the driver receives from the vehicle during running. Therefore, an expected running characteristic is not necessarily obtained if the running environment changes or the vehicle is driven by another driver. As a result, so-called driveability may deteriorate. Thus, one type of vehicle has been developed which is arranged to manually select running characteristics, such as a power output characteristic (or acceleration characteristic) and a suspension characteristic, concerning the behavior of the vehicle, by operating a mode selection switch. Namely, the vehicle is arranged to manually select a drive mode from, for example, a sporty mode in which the vehicle runs with an excellent accelerating ability, and the suspension is set to be somewhat hard, a normal mode in which the vehicle accelerates at a relatively low rate, and has a relatively soft suspension characteristic, and an eco mode in which the fuel economy or efficiency is prioritized, by operating the switch.
Also, various systems have been proposed which are configured to cause the driving orientation to be reflected by behavior control of the vehicle. This type of system does not necessitate any switching operation, and permits changes of subtle or detailed characteristics. For example, Japanese Patent Application Publication No. 06-249007 (JP-A-06-249007) describes a drive power control device using a neuro-computer configured to learn the relationship between an accelerator stroke and an acceleration corresponding to a vehicle speed as a required acceleration model and calculate the accelerator depression amount on the basis of a difference between this model and a second standard acceleration model reflecting the driver's intention and a difference between the second standard acceleration model and a reference first standard acceleration model.
The technology described in JP-A-06-249007 is a technology for causing the driver's preferences and driver's intention to be more accurately reflected by the driving performance and driving characteristics of the vehicle. However, the technology leaves room for improvement.
This invention provides a control device for a vehicle that can better adapt the dynamic performance or driving characteristics of the vehicle to driver's intention.